The present invention relates to a vehicular airbag apparatus, and particularly to a vehicular airbag apparatus of a type in which part of an airbag is retained between a portion of a retainer case and a diffuser in the retainer case.
This type of vehicular airbag apparatus has been disclosed in Japanese Patent Application Laid-Open Publication No. 10-273005.
In this conventional art, an internal space of a retainer case is partitioned by a diffuser into a gas diffusion chamber for an inflator to be disposed therein, and an accommodation chamber for accommodation of an airbag, with gas communication allowed therebetween through an opening of the diffuser. This arrangement provides a compact apparatus.
In the conventional art, however, a part of the airbag retained between a portion of the retainer case and the diffuser confronts the gas diffusion chamber, with a fear of receiving undue thermal effects of hot gases discharged from the inflator.
The present invention is made with such points in view. It therefore is an object of the present invention to provide a vehicular airbag apparatus in which a retained part of an airbag is substantially free from undue effects of hot gases.
To achieve the object, according to an aspect of the present invention, there is provided a vehicular airbag apparatus comprising: a retainer case having a first portion defining a gas diffusion chamber, a second portion defining a accommodation chamber, and a third portion between the first and second portion; a diffuser member separating the gas diffusion chamber from the accommodation chamber, with gas communication allowed therebetween through an opening of the diffuser member; and inflator disposed in the gas diffusion chamber; and airbag accommodated in the accommodation chamber, the airbag having a retained part thereof between the third portion of the retainer case and the diffuser member; and a gas invasion restrictor configured to restrict a gas invasion into between the third portion of the retainer case and the diffuser member.